<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>

<title>Code Igniter User Guide</title>

<style type='text/css' media='all'>@import url('../userguide.css');</style>
<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' />

<script type="text/javascript" src="../scripts/nav.js"></script>
<script type="text/javascript" src="../scripts/prototype.lite.js"></script>
<script type="text/javascript" src="../scripts/moo.fx.js"></script>
<script type="text/javascript">
window.onload = function() {
	myHeight = new fx.Height('nav', {duration: 400}); 
	myHeight.hide();
}
</script>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv='expires' content='-1' />
<meta http-equiv= 'pragma' content='no-cache' />
<meta name='robots' content='all' />
<meta name='author' content='Rick Ellis' />
<meta name='description' content='Code Igniter User Guide' />

</head>
<body>

<!-- START NAVIGATION -->
<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div>
<div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle.jpg" width="153" height="44" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div>
<div id="masthead">
<table cellpadding="0" cellspacing="0" border="0" style="width:100%">
<tr>
<td><h1>Code Igniter User Guide Version 1.3.3</h1></td>
<td id="breadcrumb_right"><a href="../toc.html">Full Table of Contents</a></td>
</tr>
</table>
</div>
<!-- END NAVIGATION -->


<!-- START BREADCRUMB -->
<table cellpadding="0" cellspacing="0" border="0" style="width:100%">
<tr>
<td id="breadcrumb">
<a href="http://www.codeigniter.com/">Code Igniter Home</a> &nbsp;&#8250;&nbsp;
<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
Creating Core Libraries
</td>
<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="www.codeigniter.com/user_guide/" />Search User Guide&nbsp; <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" />&nbsp;<input type="submit" class="submit" name="sa" value="Go" /></form></td>
</tr>
</table>
<!-- END BREADCRUMB -->

<br clear="all" />


<!-- START CONTENT -->
<div id="content">

<h1>Creating Core Libraries</h1>

<p>When we use the term "core libraries" we are normally referring to the base classes that are located in the <kbd>libraries</kbd>
directory and described in the Class Reference of this user guide.  In this case, however, we will instead describe how you can create your own core libraries within 
your <dfn>application</dfn> directory in order to maintain separation between your local resources and the global framework resources.</p>

<h2>Storage</h2>

<p>In order for your libraries to be stored in your <kbd>application</kbd> folder you will need to create two directories in which to store them:</p>

<ul>
<li>application/<dfn>init</dfn></li>
<li>application/<dfn>libraries</dfn></li>
</ul>


<h2>Anatomy of a Core Library</h2>

<p>A core class library consists of two components:</p>

<ol>
<li>An <kbd>init</kbd> file.</li>
<li>A <kbd>class</kbd> file.</li>
</ol>

<h2>The Init File</h2>

<p>An <kbd>init</kbd> file a small initialization file corresponding to each of your classes.  The purpose of this file is to 
instantiate a particular class. Each init file must be named identically to your class file name, adding the "init_" prefix.  For example, if your
class is named <dfn>myclass.php</dfn> your init file will be named:</p>

<code>init_myclass.php</code>

<p>Within your init file you will place your initialization code.  Here's an example of such code, using an imaginary class named <kbd>Myclass</kbd>:</p>


<code>&lt;?php  if (!defined('BASEPATH')) exit('No direct script access allowed');<br />
<br />
if ( ! class_exists('<kbd>Myclass</kbd>'))<br />
{<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;require_once(APPPATH.'libraries/<kbd>Myclass</kbd>'.EXT);<br />
}<br />
<br />
$obj =& get_instance();<br />
$obj-><kbd>myclass</kbd> = new <kbd>Myclass();</kbd><br />
$obj->ci_is_loaded[] = '<kbd>myclass</kbd>';<br />
<br />
?&gt;</code>

<h2>The Class File</h2>

<p>Your class file itself will be placed inside your <dfn>libraries</dfn> directory:</p>

<code>application/libraries/<dfn>myclass.php</dfn></code>

<p>The class will have this basic prototype:</p>

<code>&lt;?php  if (!defined('BASEPATH')) exit('No direct script access allowed');<br />
<br />
class Myclass {<br />
<br />
}<br />
?&gt;</code>


<h2>Naming Conventions</h2>

<ul>
<li>All file names must be in lowercase:  myclass.php and init_myclass.php</li>
<li>Class names must be capitalize:  class Myclass</li>
</ul>


<h2>Using Your Class</h2>

<p>From within any of your <a href="controllers.html">Controller</a> classes you can initialize your class using the standard:</p>

<code>$this->load->library('<kbd>myclass</kbd>');</code>

<p>Once loaded you can access your class using:</p>

<code>$this-><kbd>myclass</kbd>->function();</code>

<p>Note: In your init file you can define the object variable name.</p>


<h2>Passing Parameters Your Class</h2>

<p>In the library loading function you can pass data via the second parameter and it will be available to your initialization file:</p>

<code>
$params = array('type' => 'large', 'color' => 'red');<br />
<br />
$this->load->library('myclass', <kbd>$params</kbd>);</code>

<p>Parameters will be accessible using a variable called <kbd>$params</kbd>.  By default this variable is set to FALSE.</p>


<h2>Final Notes</h2>

<p>Please note that <kbd>$this</kbd> will only be available if you are calling your class from within your Controllers or View files.
If you need to access your class from elsewhere you'll need to use the <dfn>get_instance()</dfn> function to access the Code Igniter
object.  More information can be found in the <a href="ancillary_classes.html">Ancillary Classes</a> page.







</div>
<!-- END CONTENT -->


<div id="footer">
<p>
Previous Topic:&nbsp;&nbsp;<a href="libraries.html">Using Core Libraries</a>
&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
Next Topic:&nbsp;&nbsp;<a href="ancillary_classes.html">Creating Ancillary Classes</a>
<p>
<p><a href="http://www.codeigniter.com">Code Igniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006 &nbsp;&middot;&nbsp; <a href="http://www.pmachine.com">pMachine, Inc.</a></p>
</div>

</body>
</html>